Bookshelf unit



FIG. 1 is a perspective view of a bookshelf unit showing my design;

FIG. 2 is a side elevational view, the side not shown being a mirror image thereof;

FIG. 3 is an elevational view showing one of the two identical ends.

FIG. 4 is a top plan view thereof. 

The ornamental design for a bookshelf unit, as shown and described. 